102 CALIFORNIA ACADEMY OF SCIENCES. 



Type: Macrodon trahira Spix. 



This genus is composed of two species inhabiting respect- 

 ively the east and west slopes of South America. The head 

 is more elongate, the snout more pointed and the dentition 

 more formidable tlian in the other genera of tlie Erythrin- 

 incv. 



ANALYSIS OF THE SPECIES. 



a. Eleven series of scales across the back of the tail from one lateral line to 

 the other. Lat. 1. 43-44; D. 14; A. 11. Sides mottled with light and 

 dark brown. viicrolepis 1. 



aa. Nine series of scales across the back of the tail from one lateral line to 

 the other. Lit. 1. 39-43; D. 12-15; A. 10-1 L Sides plain or mottled; 

 young nsujilly with a dark lateral band. malabaricus 2. 



1. Macrodon microlepis. 



Macrodon microlepis Gthr. '64, 282 (Chagres River; Western Ecuador). 



Macrodon tahir a microlepis Steiiid. '80a, 49 i Guayaquil)). 



Habitat: Western slopes of S.Aith America from Guayaquil to Panama. 



Two specimens .05 and .365 m. from near Obispo and 

 from the Eio Chagres near Gorgona. The smaller speci- 

 men is somewhat more slender and has an indistinct dusky 

 area along the lateral line, the fins are higher and less pro- 

 fusely spotted; the pectoral is plain with an aggregation of 

 dark dots at its base. There are thirteen series of scales 

 across the back before the dorsal fin in both specimens. 



The larger specimen has the vertical fins profusely 

 spotted and barred, the bars on the caudal and anal leaving 

 only narrow light bars of the ground color. Tongue with 

 a few granular patches at its base. 



2. Macrodon malabaricus. 



Haimuri; Haimara; Huri; Canhui; Tari-irii; Trahira. 



Tareira Marcgrave, 1648, 157. 



Esox malaharkus Bloch. 1794, pt. 8, 149, pi. 392 (Trauquebar.) 



Synodus malabaricus Bl. & Schn. 1801, '• 397," 



Synodus tareira Bl. & Schn. 1801, " 398, pi. 79." 



Macrodon tareira C. & V. xix. '46, 508 (Bahia; San Francisco; Ama- 

 zon; Maracaibo). 



Erythrinus trahira Spix. '29, pi. 18; Cast. '55, 56 (Bahia). 



Macrodon trahira M. & T. '48a, 632 (all streams, especially near cas- 

 cades); Gthr. '64a (Demerara; Essequibo; Rio Capin, Para; Rio 



